Scleritis refers to a condition which results in sclera inflammation. The sclera is the white part of the eye. It is the white, solid fibrous outer layer of the eye and a kind of connective tissue. It allows the eye to preserve its shape and also gives it the white color. The sclera extends from the periphery of the cornea till the end of the optic nerve located at the posterior of the eye.
Some of the signs and symptoms of scleritis are as follows:
- Most cases of scleritis are very painful and normally accompanied by increased ocular tenderness to touch. The pain may also affect deep within and often cause the patient to awaken from sleep. This pain is what distinguishes scleritis from other conditions that result in redness of the eyes, like episcleritis or conjunctivitis.
- The reddening of the blood vessels may occur next to the sclera, and can elicit a violet or bluish tinge. Prolonged and repetitive cases of scleritis can cause thinning of the sclera leading to visibility of the brown choroid that is present beneath it.
- There may be some tearing, but abnormal discharge is generally absent.
- Visual acuity can be reduced if there is secondary clouding of the eye lens or the cornea. Buildup of the blood vessels responsible for draining the aqueous liquid from the eye can increased the intraocular pressure. On the other hand, secondary inflammation of the ciliary body, which occurs deeper than sclera, can decrease the intraocular pressure. Reduced visual acuity caused due to expansion of scleritis to the nearby tissues can result in inflammation of the front portion of the eye, swelling of the cornea, cataract, glaucoma or retinal anomalies
- Scleritis may have a lumpy appearance accompanied by several oval or circular elevations in the sclera. The portions of sclera that do not elicit redness may have experienced necrosis or death of the inflamed blood vessels.
- The discoloration of the eye may be limited to a particular section or may affected the entire white part of the eye
- Upon examination, scleritis may be found to occur either in the posterior or the anterior of the eye.
- Insertion of the extraocular muscles into the sclera can result in irritation of that specific area leading to disturbances in the movement of the eye. This may eventually result in double vision
- Certain cases of scleritis may also result in increased sensitivity to light.
Causes of scleritis
- Scleritis is a rare disorder which is distinct from episcleritis, an ocular disease that is more common. In episcleritis, the shallow tissue that lies between the layer that is filled with blood vessels, i.e., the conjunctiva and the sclera is the only part that experiences inflammation
- Nearly fifty percent of the scleritis cases are related to the presence of pre-existing conditions that occur in the internal organs of the body. Autoimmune abnormalities, connective tissue anomalies and generalized vasculitic disorders may initially elicit scleritis as the first symptom, before progressing into severe health complications
- An estimated 30 percent of the scleritis cases have no identifiable cause.
- Scleritis may also be caused due to infections by different bacteria and other microorganisms, like viruses, fungi or parasites.
- Exposure to chemicals, ocular injuries or post-surgery swelling can also result in scleritis
- Scleritis may occur in a single eye or affect both the eyes. In the latter case, the cause of scleritis is almost always the presence of an underlying systemic disease.
- Individuals who are in the age group of 40 to 50 years are at a greater risk to developing the condition. This age group has the highest incidence rate for scleritis.
- The risk to scleritis also increases with the presence of a known connective tissue or autoimmune disease
- Women are more susceptible to the disorder as compared to men
- Scleritis that is caused due to the presence of an underlying systemic condition is treated by curing the pre-existing disease, which eventually resolves scleritis.
- The above treatment may be carried out along with topical eye drop therapy. Such eye drops normally consist of topical nonsteroidal anti-inflammatory drugs or topical steroids.
- Infectious cases of scleritis may also require treatment with topical antibiotics
- In case scleritis does not have an underlying disease as the cause, then the condition is treated with different kinds of over the counter topical medications to alleviate the eye inflammation. However, they may not prove to be enough in controlling the swelling and hence prescription topical corticosteroids, NSAIDs, and anti-TNF agents may also be suggested.
- In certain cases, when the above mentioned drugs cause adverse side effects, then localized, sub-conjunctival steroid injections may provide relief
- In rare cases involving increased thinning of the sclera may require correction via surgery. In order to maintain the ocular integrity, doctors may use sclera grafts available at the eye banks to perform the surgery. Extreme thinning or perforation in the limbal region due to scleritis may require the use of corneal tissue as well.